As hydraulic control systems for a working machine, such as construction machinery, typified by a hydraulic excavator and the like, a hydraulic control system is known which is configured to have a plurality of hydraulic pumps and a plurality of actuators connected to each other via a plurality of directional control valves (valve commonly called control valves and having the function of changing the direction of hydraulic oil flow and the function of narrowing the flow passage). For such hydraulic control systems, various techniques with which operability is improved for operators are developed, and examples of this kind of art include one described in Patent Literature 1. In Patent Literature 1, a plurality of pumps and a plurality of actuators are connected via a plurality of parallel-connected directional control valves. According to the technique described in Patent Literature 1, during normal operation of a hydraulic excavator, typified by excavation work and the like, in particular, the operability can be ensured while higher fuel efficiency can be realized.